Hello, obviously ordinarily this would be a pretty open and shut PK. So I will just jump to your claims off targeting and OOC word usage.
First off, people often use this word as a buzz word to throw around without often knowing what it truly means. In this case this mugging appears to be a simple and normal opportunistic mugging. This mugging/PK situation does not inherently meet the rules definition of target mugging.
Secondly. As for your claims of them using OOC wording during the mugging. It has been deemed that their actions are not egregious enough to valid overturning this PK for that. Not to say those involved are not in the wrong for this whatsoever, they definitely shouldn’t have. But in this case it takes very little away from the mugging, the PK, and the roleplay that surrounds those two.